This invention relates to the mounting arrangements for the hydraulic motor component of a hydrostatic power transmission system, and more particularly, to a mounting system uniquely adapted to be employed on a vehicle having a unibody frame.
It is customary to provide some vehicles with unibody frames. A unibody frame refers to the utilization of the body of a vehicle to function also as a structural element. When a hydrostatic transmission system is employed in a vehicle having a unibody frame construction and the motor units are mounted opposite and independent of one another, the force created during turning and other maneuvers can subject the frame structure to extreme torsional loading. Because of the torsional loading, the unibody frame structure can experience early failure. In addition, the stability of the structure during maneuvers is decreased. This condition is applicable to some varieties of lawn and garden tractors. The problem of torsional loads on a unibody frame lawn and garden tractors is amplified when a working implement is supported by the vehicle.
It is possible to decrease the susceptibilty of a unibody frame vehicle to torsional loading by employing vehicle components such as the vehicle engine as a stiffening agent for the vehicle. However, the use of vehicle component as stiffening agents will require component hardening which will introduce significant increases in cost and weight to the vehicle. Another means to reduce the susceptibility of a vehicle to torsional load is to provide independent stiffeners, however, present methods have not proved totally satisfactory.